LOUISVILLE, Ky. (LEX 18) — The Louisville Zoo is mourning the loss of Heran, a 16-year-old Sumatran tiger.
Heran was suffering from B-cell lymphoma and leukemia, a type of blood cancer. The zoo had to make the difficult decision to humanely euthanize the male tiger.
Guests recognized Heran with his missing eye, which gave him a permanent “winking” appearance. Heran arrived in Louisville in 2017 from the Illinois Miller Park Zoo.
Heran had a mature cataract and was diagnosed with glaucoma in his right eye. To ease his pain, zoo officials decided to surgically replace the eye with a silicone orbital implant. He quickly recovered and was able to adapt to his new home.
Sumatran tigers, which are the smallest subspecies of tigers, are endemic to Indonesia and classified as critically endangered. There are only about 75 Sumatran tigers in zoological parks in North America.
Heran came to the Louisville Zoo through a recommendation by the Sumatran Tiger Species Survival Plan (SSP). Despite attempted pairings, he, unfortunately, did not sire any cubs.
To preserve Heran’s genetic value, the Sumatran Tiger SSP recommended semen collection and gamete rescue as part of the euthanasia plan.
"The priority is to do right by the animal in providing compassionate end-of-life care," said Dr. Zoli Gyimesi, Senior Staff Veterinarian. "But if we can also do what is right for the population that Heran represented as an ambassador, that’s our responsibility as well. We hope that the samples we collected will let Heran sire cubs in the future."
Tissues collected from the tiger after euthanasia were also submitted to researchers at two veterinary universities. One university is part of an effort to biobank and characterize cancers across zoo species, and the other researches stem cell therapies for living tigers. “With every sad loss,” said Zoo Director Dan Maloney, “we try to maximize what can be learned to benefit future generations of animals.”